"We've almost got some of their telecommunications cracked; the front end even runs on a laptop!" The Mac that sunk a thousand ships could have been merely clunky product placement, not a bafflingly stupid tech-on-film moment.

Wasn't the in-movie explanation for that that all modern tech was secretly based on reverse engineered alien tech?

DBZ fan. Lots of things:

• SSJ4 could be canon. It just requires a full moon and a tail. When all the Saiyans in-universe don't have them, it's kinda impossible...
• Becoming SSJ easily (Goten and Trunks) is easily explained by saying that because their fathers already were SSJ by the time of conception, it had become a natural reflex to them, rather than a barrier that needed to be broken.
• They've been able to blow up planets since the days of 9000 power levels, probably even with 1000, yet with power levels of 1B the fights are largely the same. Explain this as some sort of ki concentration, where your energy has...more energy per energy, or something?
• Goku's "telepathy" was always just him feeling someone's energy, and feeling how flustered and overwhelmed they are. He does a similar thing to Future Trunks, but it wasn't called telepathy, it was "searching his emotions" - another BS way of saying "shit, you don't look good, what's up!".
• The Dragon Balls take a year to charge, but are often usable pretty much right away - the RR army get them 8 months after they were used, and despite being used to revive Goku the Earth balls are used basically a month later because Kami is revived. Maybe just explain it as Kami needing time to revive them as they're intrinsically linked? It Kami goes on bed rest, you'll have Dragon Balls in a few weeks...
• Launch didn't disappear. She married Tien, they have kids, and she stays at home to raise them.

I could probably write a book to "fix" the show, but these fixes just tend to annoy fans because they want a "canon" answer to a show that is hilariously broken.

The Usual Suspects

Spoilers below:

At one point a character (I think it was Giancarlo Esposito, but not certain) mentions an English lawyer, to which another (Chazz Palminteri, I think) says >!"Kobayashi?"!<

!GE nods. But since Kobayashi is not Pete Postlethwaite's character's real name, just the name on the bottom of a coffee cup, this makes no sense.!<

!Could have been fixed by GE saying, "Probably" or "Yeah, maybe" or whatever.!<